JP2007077585A - Tunnel construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel construction method for constructing an underground gallery which can prevent leakage of noxious materials eluting from waste over a very long period of time. <P>SOLUTION: According to the tunnel construction method for constructing the underground gallery where the waste is embedded and disposed of, a plurality of support members 4 in a pit excavated in the ground G, extending in a pit circumferential direction, are arranged side by side at intervals in a pit axial direction, and a plate member 6 is sandwiched between the support members 4, 4 adjacent to each other, followed by filling a clay-based water cutoff material 7 containing a swelling clay material in a gap between the plate member 6 and a pit wall surface 2a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tunnel construction method for constructing an underground tunnel for burying waste.

  As a method of disposing of the waste, there is a method of storing the waste in an underground mine constructed in the ground and then backfilling the mine to bury the waste. When disposing of waste by this method, it is necessary to prevent leakage of harmful substances eluted from the waste. Therefore, conventionally, a tunnel construction method for constructing a waste treatment tunnel has employed a method of lining the wall surface of the excavated mine with concrete or the like.

In the case of burying radioactive waste, the waste is placed in an underground mine with the waste surrounded by a shielding material made of bentonite or the like. Thereby, the leakage to the groundwater of the radioactive substance extracted from a radioactive waste can be suppressed (for example, refer patent document 1).
JP 2005-144278 A

  However, in the conventional tunneling method described above, the permeability of the lining covering the mine wall increases due to the deterioration over a long period of thousands or thousands of years, and harmful substances eluted from the waste leak into the surrounding ground. There is a problem that it may be possible. Also, in the conventional tunneling method, cement components are eluted from cement-based members such as linings after a very long period of time, and the bentonite shielding material surrounding the waste is made of the material due to the calcium component and high alkalinity of this cement component. There is a problem that it deteriorates and cannot ensure its low water permeability, and there is a risk of leakage of radioactive substances into groundwater.

  The present invention takes into consideration the above-described conventional problems, and provides a tunnel construction method capable of constructing an underground tunnel capable of suppressing leakage of harmful substances eluted from waste for an extremely long period of time. The purpose is that.

  The invention according to claim 1 is a tunnel construction method for constructing an underground tunnel for burying and disposing of waste, and a plurality of support members extending along the circumferential direction of a mine excavated in the ground are provided. Axial spacing is provided side by side, a plate-like member is sandwiched between adjacent support members, and a clay-based waterstop material containing a swellable clay material is filled between the plate-like member and the well wall surface. A tunnel construction method characterized by

  Due to such characteristics, the clay-based waterstop material filled between the plate-like member and the wall surface of the mine is supported by the support member and the plate by the water-swelling swelling of the swellable clay material contained therein receiving the supply of groundwater. The space between the support member and the wall surface of the pit is filled with the space between the support member and the wall surface. Further, since a clay-based water-stopping material is used instead of a cement-type water-stopping material, the cement component is not eluted. Further, when the supporting member or the like is deteriorated due to corrosion and a defective portion is generated due to the elapse of an extremely long period of time, the swellable clay material contained in the clay-based waterstop material swells and fills the defective portion.

  The invention according to claim 2 is the tunnel construction method according to claim 1, in which a clay-based waterstop material is packed in a flexible and water-permeable bag body, It is characterized by filling the clay-based waterstop material between the plate-like member and the wall surface of the pit by stuffing them in between.

  Due to these characteristics, groundwater infiltrates into the water-permeable bag, and the swelling clay material contained in the clay-based water blocking material packed in the bag swells, thereby allowing flexibility. The shape of the bag is deformed, and the space formed between the support member and the wall surface of the pit and other gaps are filled evenly and densely.

  According to the tunnel method according to the present invention, the swellable clay material contained in the clay-based waterstop material is supplied with groundwater and absorbs and swells, so that the clay-based waterstop material is closely packed without gaps, Support structure (lining structure) consisting of support members, plate-like members and clay-based water-stopping material exerts a water-stopping effect, reduces spring water from the pit wall, and leaks harmful substances eluted from waste It is possible to construct an underground mine that can suppress the above. In addition, by using a clay-based water-stopping material instead of a cement-based water-stopping material, the cement component will not be eluted after a very long period of time. For example, when processing radioactive waste, It is possible to construct an underground mine that can prevent leakage for a very long time without deterioration of the shielding material made of bentonite or the like formed around the waste. Furthermore, when the supporting member or the like is deteriorated by corrosion due to the passage of a very long period of time and a defective part is generated, the swellable clay material contained in the clay-based waterstop material swells and fills the defective part. It is possible to construct an underground mine that can suppress leakage for an extremely long time.

  In addition, by filling a bag body having flexibility and water permeability with a clay water-stopping material between the plate-like member and the pit wall surface, the gap between the plate-like member and the pit wall surface can be obtained. If the clay-based waterstop material is filled in, the clay-type waterstop material will be filled evenly and densely between the plate-like member and the wall surface of the mine. There is no need to reduce equipment costs, and even when the face of the mine is small in diameter and the filling equipment cannot be installed, a clay-type waterstop material is filled between the plate-like member and the pit wall surface. Can do.

  Hereinafter, the first and second embodiments of the tunnel construction method according to the present invention will be described with reference to the drawings.

[First embodiment]
First, the structure of the underground mine 1 for burying waste will be described.
FIG. 1 is a cross-sectional view showing an underground mine 1, and FIG. 2 is a cross-sectional view taken along a line AA shown in FIG. As shown in FIGS. 1 and 2, the underground mine 1 is constructed with a lining (tunnel support 3) covering the mine wall surface 2 a inside the mine 2 formed in the ground G made of soft rock, for example. Consisting of

  FIG. 3 is an enlarged cross-sectional view showing a part of the tunnel support 3, and FIG. 4 is a cross-sectional view between BB shown in FIG. 3. As shown in FIGS. 1, 2, 3, and 4, the tunnel support 3 includes a plurality of support members 4 extending along the circumferential direction of the pit 2 and adjacent support members 4, 4. A plurality of connecting members (tie rods 5) to be connected, a plurality of plate-like members 6 interposed between the adjacent support members 4 and 4, and the plate-like members 6 and the well wall 2a are filled. It is composed of a clay-based waterstop material 7.

  The supporting members 4 are formed by joining a plurality of long steel materials 8 such as H-shaped steel and I-shaped steel with bolts or the like, and the arch portion 2b, side wall portions 2c, 2c, and inverted portion 2d of the pit 2. Are provided along each of them, and are formed in an annular shape. A plurality of support members 4 are provided in the pit 2, and the plurality of support members 4... Are arranged at predetermined intervals in the axial direction of the mine 2 and are arranged in a rib shape in the mine 2. Each of the long steel members 8 is disposed in a direction in which the outer flange 8a faces the well wall surface 2a and is bent along the well wall surface 2a.

  The tie rods 5 are rod-shaped members that extend in a direction parallel to the axis of the pit 2 and are spanned between adjacent support members 4, 4. The webs 8 b of the long steel members 8, 8 facing each other. The main body 5a is formed of a steel pipe having a circular cross-sectional shape interposed between 8b, and a fixture 5b for fixing the main body 5a to the webs 8b, 8b of the long steel members 8, 8 on both sides from the back. . The plurality of tie rods 5 are arranged in parallel at predetermined intervals along the extending direction of the support member 4.

  The plate-like members 6 are made of corrugated steel plates such as deck plates and skin plates. The plate-like members 6 are fitted between the long steel members 8 and 8 (between the support members 4 and 4) which are parallel to each other in a state where both ends thereof are in contact with the back surface of the inner flange 8a '(protrusion). It is installed in a state where a gap is opened between the pit wall surface 2a.

  The clay-based waterstop material 7 is a liquid, granular or viscous water-stop material containing a swellable clay material (bentonite) which swells when moisture is added. For example, bentonite powder or It may be a clay-based water-stopping material 7 made only of swelling clay material such as bentonite granular material (granular material), bentonite raw ore pulverized material, or a mixed material in which sand or gravel is mixed with the swelling clay material. The clay-based waterstop material 7 may be used. The clay-based water blocking material 7 is densely filled in a range surrounded by the adjacent support members 4, 4, the plate-like members 6, and the pit wall surface 2 a, and further supplies groundwater from the pit wall surface 2 a. By receiving and swelling, the gap between the outer flange 8a of the long steel material 8 and the well wall surface 2a is filled densely.

Next, the tunnel construction method constructed by the underground mine 1 having the above-described configuration will be described.
FIG. 5 is a perspective view showing a built-in state of the tunnel support 3 constructed in the underground mine 1.
First, as shown in FIGS. 1 and 2, an excavation process for forming a pit 2 in the ground G is performed. Specifically, the excavator or the like excavates for one span of the tunnel support 3 at the face of the tip of the mine 2.

  Next, as shown in FIGS. 3, 4, and 5, a plurality of support members 4... The support assembly process of connecting with tie rods 5 is performed. Specifically, the long steel members 8 are arranged at predetermined positions along the pit wall 2a of the pit 2, and the adjacent long steel members 8 and 8 are joined together and assembled into an annular shape, thereby supporting each supporting member. 4 ... are formed. At this time, the main body 5a of the tie rod 5 is disposed at a predetermined position between the adjacent support members 4 and 4, and both ends of the main body 5a are connected to the long steel members 8 and 8 on both sides from the back of the webs 8b and 8b. It fixes with the fixing tools 5b and 5b, respectively.

  Next, while sandwiching a plurality of plate-like members 6 between the adjacent support members 4, 4, a clay-based waterstop material 7 is filled into a space formed between the plate-like members 6. Perform the lining process. Specifically, first, the plate-like member 6 is put on the back side of the inner flanges 8a 'and 8a' of the adjacent support members 4 and 4, and both ends thereof are placed on the back surfaces of the inner flanges 8a 'and 8a' on both sides. Build them in contact with each other. At this time, the plate-like member 6 and the supporting members 4 and 4 on both sides may be joined by welding or the like. Subsequently, the clay-based waterstop material 7 is placed in the space generated on the back side of the plate-like member 6 by the filling equipment 10 installed in the pit 2. The filling facility 10 includes a funnel-shaped hopper 11 for storing the clay-based waterstop material 7, a supply pipe 12 connected to the discharge port 11 a of the hopper 11, and a flexible hose 13 connected to the distal end portion 12 a of the supply pipe 12. And the compressor 14 connected to the base end portion 12b of the supply pipe 12, and the clay water-stopping material 7 in the hopper 11 flows into the supply pipe 12 from the discharge port 11a and from the compressor 14. Air is compressed by compressed air sent into the supply pipe 12 and flows out of the supply pipe 12 from the tip of the flexible hose 13 through the flexible hose 13. After the clay-based waterstop material 7 is filled up to the vicinity of the upper end of the plate-like member 6, the clay-type waterstop material 7 filling operation is temporarily stopped, and after the plate-like member 6 is installed, the clay-type waterstop material is again used 7 filling operation is started. By repeating the installation work of the plate-like member 6 and the filling work of the clay-based waterstop material 7, the space between the support members 4 and 4 is closed.

  Next, returning to the excavation process for excavating one span of the tunnel support 3 described above, the support assembly process and the lining process are performed, and the underground mine 1 is sequentially constructed for each span.

  According to the tunnel construction method having the above-described configuration, a plurality of support members 4... Are arranged side by side in the axial direction of the well 2 inside the well 2 excavated in the ground G, and adjacent support members 4. , 4 is sandwiched between the plate-like members 6... And the clay-type water-stopping material 7 containing the swellable clay material is filled between the plate-like members 6. When the swellable clay material contained in the water is swollen by receiving groundwater, the clay-based waterstop material 7 is brought into close contact with the support members 4 and the plate-like members 6 without any gaps, and the outside of the support member 4. The gap formed between the flange 8a and the pit wall surface 2a is also filled, and the gap is densely filled with no gap. As a result, the tunnel support 3 (support structure) composed of the support members 4, the plate-like members 6, and the clay water-stopping material 7 exhibits a water-stopping effect, and the spring water from the pit wall surface 2 a is reduced. It is possible to construct an underground mine 1 that can suppress leakage of harmful substances eluted from waste.

  Further, since the clay-based water-stopping material 7 is used instead of the cement-type water-stopping material, the cement component is not eluted even after an extremely long period of 1000 years or 10,000 years. As a result, for example, when embedding radioactive waste, the underground mine 1 that can suppress leakage for an extremely long time without the material deterioration of the shielding material made of bentonite or the like formed around the waste is constructed. can do.

  Further, since the clay-based waterstop material 7 containing the swellable clay material is used, even if the supporting member 4... Or the plate-like member 6. The swellable clay material contained in the clay-based waterstop material 7 absorbs water and swells to fill the defective portion. Thereby, the underground mine 1 which can control the leakage over a super-long term can be constructed.

[Second Embodiment]
Next, a second embodiment of the tunnel method according to the present invention will be described. In addition, about the structure similar to 1st embodiment mentioned above, the description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 6 is a perspective view showing a built-in situation of the tunnel support 3 constructed in the underground mine 1. As shown in FIG. 6, a plurality of sandbags (water stop bodies 21) in which a clay water stop material 7 is packed in a bag body 20 are prepared in advance. And after performing the support assembly process which assembles several support member 4 ..., while sandwiching several plate-shaped member 6 ... between the adjacent support members 4, 4, between the plate-shaped member 6 ... and the pit wall surface 2a, The clay water-stopping material 7 is filled between the plate-like members 6 and the pit wall surface 2a by filling a plurality of water-stopping bodies 21 prepared in advance into the space formed therebetween.

  The bag body 20 is made of a material having flexibility that can be easily changed in shape and water permeability that allows inflow or infiltration of groundwater. For example, a plastic bag having a large number of holes, a mesh-like resin net bag, a water-permeable cloth bag, and the like.

  When the waterstop 21 has been packed to the vicinity of the upper end of the plate member 6, the filling operation of the waterstop 21 is temporarily stopped, and after the installation work of the plate member 6, the waterstop 21 is started again. By repeating the installation work of the plate-like member 6 and the filling work of the waterstop 21, the support members 4 and 4 are closed.

  According to the tunnel construction method having the above-described configuration, not only the same operational effects as the first embodiment can be achieved, but also further operational effects can be achieved. That is, by filling the bag 20 having flexibility and water permeability with the clay-based waterstop material 7 between the plate-like member 6 and the pit wall surface 2a, the plate-like member 6 and Since the clay-based waterstop material 7 is filled between the wall surface 2a and the water-permeable bag body 20, groundwater infiltrates into the bag body 20, and the clay-type waterstop material packed in the bag body 20 As the swellable clay material contained in 7 swells, the shape of the flexible bag 20 is deformed, and a space or other gap formed between the outer flange 8a of the support member 4 and the well wall surface 2a. Evenly and densely packed. As a result, it is not necessary to prepare the filling facility 10 as in the first embodiment described above, the facility cost can be reduced, and the face of the pit 2 has a small diameter and is filled as shown in FIG. Even when the facility 10 cannot be installed, the clay-based waterstop material 7 can be filled between the plate-like members 6 and the pit wall surface 2a.

  The first and second embodiments of the tunnel method according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the scope of the present invention. is there. For example, in the above-described first and second embodiments, the support member 4 is provided along each of the arch portion 2b, the side wall portions 2c, 2c, and the invert portion 2d of the pit 2, and is formed in an annular shape. However, when the ground is hard, the present invention may be a gate-shaped support member provided along the arch and side walls of the mine.

  In the first and second embodiments described above, a corrugated steel plate is used as the plate-like member 6, but the present invention is not limited to this, and for example, a flat steel plate is used. Alternatively, a wooden board or the like may be used.

  In the first embodiment described above, the filling facility 10 in which the hopper 11 and the compressor 14 are installed at the face of the pit 2 is used. However, the present invention is limited to this filling facility 10. Instead, for example, it may be a filling facility in which a hopper or a compressor is installed behind the face, and the supply pipe is piped up to the face, or other clay filling system between the plate-like member and the pit wall surface. You may fill with a water stop material.

  In the first embodiment described above, a method of filling the clay-based waterstop material 7 from above between the pit wall surface 2a and the plate-like member 6 is employed. The method is not limited, and for example, an inlet may be provided in advance in the flange of the plate-like member or the supporting member, and the clay-based waterstop material may be filled from the inlet.

  In addition, as a method of filling the clay-based waterstop material 7 between the plate-like member 6... And the pit wall surface 2a, in the first embodiment, filling is performed using the filling equipment 10, and the second In the embodiment, a method of filling the clay water-stopping material 7 in the bag body 20 and stuffing it is adopted. However, the present invention uses the above two methods in combination to fill the clay water-stopping material. You may do the work.

It is sectional drawing showing the underground mine for demonstrating 1st embodiment which concerns on this invention. It is sectional drawing between AA shown in FIG. It is a fragmentary sectional view showing the detail of the underground mine for demonstrating 1st embodiment which concerns on this invention. It is sectional drawing between BB shown in FIG. It is a perspective view showing the construction situation for explaining a first embodiment concerning the present invention. It is a perspective view showing the construction situation for explaining a second embodiment concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underground mine 2 Mine 2a Mine wall surface 4 Support member 6 Plate-shaped member 7 Clay-based waterproofing material 20 Bag G Ground

Claims (2)

In the tunnel construction method of constructing underground tunnels to bury waste,
Within the mine excavated in the ground, a plurality of support members extending along the circumferential direction of the mine, are arranged side by side in the direction of the mine shaft,
A plate-like member is sandwiched between adjacent support members,
A tunnel construction method characterized by filling a clay-based waterstop material containing a swellable clay material between a plate-like member and a wall surface of a mine. In the tunnel construction method according to claim 1,
Clay between the plate-like member and the pit wall surface is packed between the plate-like member and the pit wall surface by filling a clay body water-stopping material in a flexible and water-permeable bag body. A tunnel construction method characterized by filling a water-stopping material.

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